Crank-case ventilation



Filed April 30, 1928 Patented Jan. 14, 1930 PATENT OFFICE HERBERT G. KAMlR-ATH, OF FLINT, MICHIGAN, ASSIGNOR TO A C SPARK PLUG- COM- PANY, F FLINT, MICHIGAN, A COMPANY OF MICHIGAN CRANK-CASE, VENTILATION Application filed April 30,

ents so as to maintain the lubricating oil in good conditlon. It is undesirable to pass too great a column of air through the crank case as would normally occur at hlgh engine speeds for the result would be to draw out considerable quantities of lubricating oil. It

- gine.

is also recognized as desirable that both the air supplied to the crank case and to the engine be passed through an air cleaner to prevent the admission of grit to the engine.

My invention consists in a convenient arrangement wherebya single air cleaner serves to clean the air supplied both to the engine and the crank case and whereby the ventilation is controlled so that it will never become excessive. To accomplish this I connect the air cleaner to the engine intake by two parallel passages, one of which includes the crank case, and provide a suction controlled valve in the passage going directly to the en- This valve is normally closed so that all of the engine air supply is taken through the air cleaner by way of the crank case. When the engine air consumption increases the valve opens and the main portion of the supply is taken directly from the cleaner.

For simplicity I prefer to make the valve compartment a part of the passage leading air directly from the cleaner to the engine, the valve compartments being preferably separated by a partition in which the suction controlled valve is located. The valve com partments normally communicate with the crank case through openings provided around the valve tappets- If desired the air cleaner may be omitted, the system then merely acting to prevent excessive ventilation.

Figure 1 is a horizontal section through an internal combustion engine showing my ventilating arrangement applied thereto.

Figure 2 is a side view of the construction of Figure 1.

Figure 3 is a section through the control valve and Figure 4 is a view on line 4-4 of Figure 1.

1928. Serial No. 274,145.

1( indicates an internal combustion engine having cylinders 12 and provided with compartments 14 and 16 at the sides of the cylinders. These compartments house the usual valves and push rods (not shown), the latter 1 reciprocating in uides 18. Apertures 20 are provided about t 1e guides in the usual manner permitting the draining of oil back into the crank case. The compartment 14 is provided with a cover 22 and the compartment 16 with a cover 24. Upon cover 24 is mounted an air cleaner 26. This cleaner may be of the centrifugal type, the filter type, or of any other character preferred. To the cover 22 is clamped a conduit 28 leading to the car'- buretor 3O connectedto the manifold 32.

The valve compartments 14 and 16 are separated by a partition 34 and in this partition is mounted the control valve 36 best shown in Figure 3. This valve consists of a simple disk 38 held upon its seat by coiled spring 40. The other end of the spring bears against washer 42 encircling bolt 44 secured to the partition- Referring to Figure 4 it will be noted that baffle 45 is provided over the entrance to the conduit 28.

When the engine is operating under light load but a small quantity of air is consumed and this is drawn from the atmosphere by way of the air cleaner 26, the valve compartment 16, the passages 20 around the guides 18, into the crankcase. The air is drawn out of the crankcase through similar openings 20 into valve compartment 14 and from the valve compartment through conduit 28 into the carburetor air intake. The volume of air passing through the crankcase is sufficient to insure the evaporation of diluents and yet not so great as to draw out the oil. As the engine takes on more load its air consumption increases with the result that greater suction is applied to the valve compartment 14, and when this reaches a sufficiently high value, valve 38 isdrawn off its seat and airpasses directly from valve compartment 16 into valve compartment 14 without going through the crankcase. Under these circumstances the ventilation of the crankcase will be very greatly reduced so that there will be no possibility of drawing oil out of the crankcase.

At the same time the crankcase vapors will be drawn into the engine in sutficient volume to prevent any serious dilution. The baflie 45 will serve to guard the air outlet 28 against the entrance of oil particles and these will trickle down the walls of the valve compartment and drain back into the crankcase through the openings 20.

My invention is capable of considerable modification. It is not limited to application to valve compartments for these merely form a passage connecting the air cleaner and the air outlet in parallel with the passage through the crankcase. The valve shown at 36 is merely an example of one type of valve which may be used for this purpose.

I claim:

1. The combination of an engine having an air intake, a crank case, and a pair of compartments in communication with the crank case, an air cleaner connected to one of said compartments, a connection from the other compartment to the engine intake, a passage connecting said compartments, and means normally substantially closing said passage but adapted to open upon increase in engine suction to permit the passage of air directly from the air cleaner through the compartments to the engine intake.

2. The combination of an engine having an air intake, a crank case, and a pair of compartments in communication with the crank case, an air cleaner connected to one of said compartments, a connection from the other compartment to the engine intake, a passage connecting said compartments, means normally substantially closing said passage but adapted to open upon increase in engine suction to permit the passage of air directly from the air cleaner through the compartments to the engine intake, said compartments housing the usual valve mechanism, and the passage between said compartments being formed in a partition separating them.

3. The combination of an engine having an air intake, a crank case, and a pair of compartments in communication with the crank case, an air cleaner connected to one of said compartments, a connection from the other compartment to the engine intake, a passage connecting said compartments, and means normally substantially closingsaid passage but adapted to open upon increase in engine suction to permit the passage of air directly from the air cleaner through the compartments to the engine intake, said compart ments housing the usual valve mechanism, and the passage between said compartments being formed in a partition separating them, said compartments being provided with covers upon one of which said air cleaner is mounted and upon the other of which the engine intake connection is mounted.

4. The combination of an engine having an air intake, a crank case, and a pair of 

